Plasma from patients with HIT induces TF in PBMCs. Plasma from healthy volunteers (n = 3) and from patients with HIT (n = 3) was heat-inactivated and used in the place of RTO and KKO, respectively. (A) TF activity in PBMCs. (B) MP TF activity in MPs isolated from the cell supernatant fluid. ***P < .001, **P < .01, and *P < .05 compared with control.